((a)) ** .—** In this section:
((1)) ** .—** The term “challenge cost-share agreement” means any agreement entered into between the Secretary and any cooperator for the purpose of sharing costs or services in carrying out authorized functions and responsibilities of the Secretary with respect to any System unit or System program, any affiliated area, or any designated national scenic trail or national historic trail.
((2)) ** .—** The term “cooperator” means any State or local government, public or private agency, organization, institution, corporation, individual, or other entity.
((b)) ** .—** The Secretary may negotiate and enter into challenge cost-share agreements with cooperators.
((c)) ** .—** In carrying out challenge cost-share agreements, the Secretary may provide the Federal funding share from any funds available to the Service.